Many contemporary debates about American social life are premised on the notion that everything is changing—that with the rise of same-sex couples, single-parent households, and pre-marital sex, American family structure looks much different today than it did in the more conservative mid-20th century period. But in at least one important respect, the opposite is true. A new Pew Research Center report shows that, as a growing share of young people choose to live with their parents after turning 18, the multi-generational family is making a comeback:

A larger share of young women are living at home with their parents or other relatives than at any point since the 1940s.

A new Pew Research Center analysis of U.S. Census Bureau data shows that 36.4% of women ages 18 to 34 resided with family in 2014, mainly in the home of mom, dad or both. The result is a striking U-shaped curve for young women – and young men – indicating a return to the past, statistically speaking.

You’d have to go back 74 years to observe similar living arrangements among American young women. Young men, too, are increasingly living in the same situation, but unlike women their share hasn’t climbed to its level from 1940, the highest year on record.

What accounts for the shift? It probably can’t be attributed entirely to the Great Recession, both because the share of young people living with their parents has been ticking upward for decades and because the improving job market over the past few years hasn’t reversed the trend. In August, we listed a few other factors that might be at play in this story: rising ethnic diversity and immigration (young second-generation Americans are more likely to live with their parents than young people whose families have been in the United States for three or more generations), more liberal attitudes toward sexuality (20 somethings might feel less pressure to get out of their parents’ house if they can bring over romantic partners), and the growing number of single parents (who might be more eager for extra companionship than married couples).

In other words, many of the trends associated with progressivism might be reproducing a family structure from social conservatism’s heyday. We live in interesting times.